Weak Lensing Peaks in Simulated Light-Cones: Investigating the Coupling between Dark Matter and Dark Energy

TL;DR

This study explores how weak lensing peak statistics in simulated light-cones can differentiate between dark energy models, especially those with coupling to dark matter, by analyzing their impact on structure formation and observable lensing signals.

Contribution

It demonstrates that weak lensing peak counts can effectively distinguish coupled dark energy models from standard cosmology using simulated light-cones.

Findings

Peak counts vary by about 20% between models with different dark energy couplings.

Peak statistics can differentiate dark energy models with the same power spectrum normalization.

Approximately 70% of clusters contribute to detectable weak-lensing peaks with S/N > 2.

Abstract

In this paper, we study the statistical properties of weak lensing peaks in light-cones generated from cosmological simulations. In order to assess the prospects of such observable as a cosmological probe, we consider simulations that include interacting Dark Energy (hereafter DE) models with coupling term between DE and Dark Matter. Cosmological models that produce a larger population of massive clusters have more numerous high signal-to-noise peaks; among models with comparable numbers of clusters those with more concentrated haloes produce more peaks. The most extreme model under investigation shows a difference in peak counts of about $20\%$ with respect to the reference $\mathrm{\Lambda}$CDM model. We find that peak statistics can be used to distinguish a coupling DE model from a reference one with the same power spectrum normalisation. The differences in the expansion history and the growth rate of structure formation are reflected in their halo counts, non-linear scale features and, through them, in the properties of the lensing peaks. For a source redshift distribution consistent with the expectations of future space-based wide field surveys, we find that typically seventy percent of the cluster population contributes to weak-lensing peaks with signal-to-noise ratios larger than two, and that the fraction of clusters in peaks approaches one-hundred percent for haloes with redshift z$\leq$0.5. Our analysis demonstrates that peak statistics are an important tool for disentangling DE models by accurately tracing the structure formation processes as a function of the cosmic time.